Servlet与Jsp的结合使用实现信息管理系统二
PS：前面说了抽取框架的搭建，接着就要我们开始进入网址的时候就要查到全部信息并显示在首页，我们用到的MySql数据库，具体步骤是：
- 创建数据库，创建表，添加信息
- 项目中调入mysql的jar包 mysql-connector-java-5.1.18-bin.jar
- 单独一个类写JDBC连接数据库
- 查询的Sql语句及方法
- 删除sql语句及方法
- 增加sql语句及方法
- 修改sql语句及方法
- xml配置文件的设置
- mainservlet中写相应操作
1：创建数据库，创建表，添加信息
2：项目中调入mysql的jar包 mysql-connector-java-5.1.18-bin.jar
自行导入即可
3：单独一个类写JDBC连接数据库
/**
* 开启数据库连接
* */
public void getConnect() {
String driver = "com.mysql.jdbc.Driver";
// URL指向要访问的数据库名，设置编码
String url = "jdbc:mysql://127.0.0.1:3306/ceshi1?useUnicode=true&characterEncoding=utf-8";
// MySQL配置时的用户名
String user = "root";
// Java连接MySQL配置时的密码
String password = "root";
try {
// 加载驱动程序
Class.forName(driver);
// 连续数据库
conn = DriverManager.getConnection(url, user, password);
if (!conn.isClosed())
System.out.println("Succeeded connecting to the Database!");
// statement用来执行SQL语句
statement = conn.createStatement();
// 要执行的SQL语句
String sql = "select * from information";
} catch (Exception e) {
System.out.println("连接失败");
}
}
/**
* 断开数据库连接*/
public void disConnect() throws SQLException {
if(conn!=null){
conn.close();
statement.close();
}
}
下面是增删查改，查询数据和查询单条数据都是返回一个list集合，原本是可以写成一个方法的，但为了清楚显示，就单独写了。在这之前呢，要先写一个model类
public class Information {
String name,banji,qq,shouji,zhuangtai;
int id,age;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getBanji() {
return banji;
}
public void setBanji(String banji) {
this.banji = banji;
}
public String getQq() {
return qq;
}
public void setQq(String qq) {
this.qq = qq;
}
public String getShouji() {
return shouji;
}
public void setShouji(String shouji) {
this.shouji = shouji;
}
public String getZhuangtai() {
return zhuangtai;
}
public void setZhuangtai(String zhuangtai) {
this.zhuangtai = zhuangtai;
}
}
/** * 查询全部数据,返回list集合 * String sql = "select * from information"; */ public List<Information> queryAllData() throws SQLException { List<Information> list = new ArrayList<Information>(); String sql = "select * from information"; ResultSet rs = statement.executeQuery(sql); while (rs.next()) { System.out.print(rs.getInt("id")); information = new Information(); information.setId(rs.getInt("id")); information.setName(rs.getString("name")); information.setAge(rs.getInt("age")); information.setBanji(rs.getString("banji")); information.setQq(rs.getString("qq")); information.setShouji(rs.getString("shouji")); information.setZhuangtai(rs.getString("zhuangtai")); list.add(information); } return list; } /*** *插入数据 */ public int addData(String sql) { int a = 0; try { a = statement.executeUpdate(sql); System.out.print("插入成功"); } catch (SQLException e) { System.out.print("插入失败"); e.printStackTrace(); } return a; } /*** *删除数据 */ public void deleteData(String sql) { try { statement.executeUpdate(sql); System.out.print("删除成功"); } catch (SQLException e) { System.out.print("删除失败"); e.printStackTrace(); } } /** * 查询单条数据,返回一个list集合,为了是在用户修改的时候,把数据带到指定页面 */ public List<Information> updataData1(String sql) { try { list1 = new ArrayList<Information>(); ResultSet rs = statement.executeQuery(sql); while (rs.next()) { information = new Information(); information.setId(rs.getInt("id")); information.setName(rs.getString("name")); information.setAge(rs.getInt("age")); information.setBanji(rs.getString("banji")); information.setQq(rs.getString("qq")); information.setShouji(rs.getString("shouji")); information.setZhuangtai(rs.getString("zhuangtai")); list1.add(information); } System.out.print("查成功"); } catch (SQLException e) { System.out.print("查失败"); e.printStackTrace(); } return list1; } /** * 更改数据,如果成功返回1 */ public void updataData2(String sql) { try { int num = statement.executeUpdate(sql); System.out.print("更改成功"); } catch (SQLException e) { System.out.print("更改失败"); e.printStackTrace(); } }
4：xml配置文件设置拦截，只要是后面带.do的都拦截。
<servlet-mapping>
<servlet-name>mainservlet</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>mainservlet</servlet-name>
<servlet-class>control.MainServlet</servlet-class>
</servlet>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
5：mainservlet中写相应操作
5.1在网页加载的时候就调用数据库查询全部数据，并返回到首页，首先要对页面编码设置
response.setContentType("text/html;charset=utf-8");
request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("UTF-8");
然后要获取地址栏中的url地址，该地址是8080后面的字符串
String str = request.getRequestURI();
拦截字符串进行equals比较，
//查询全部:
connecDatabase();//连接数据库 if (str.equals("/MyTest.do")) { queryAllData(request, response); }
queryAllData(request,response)方法，把获取到的数据转发到指定jsp
private void queryAllData(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
listAll = new ArrayList<>();
try {
listAll = daoConnection.queryAllData();
daoConnection.disConnect();
request.getSession().setAttribute("listAll", listAll);
request.getRequestDispatcher("index.jsp").forward(request, response);
} catch (SQLException e) {
e.printStackTrace();
}
}
/**
* 连接数据库
* */
public void connecDatabase(){
daoConnection = new DaoConnection();
daoConnection.getConnect();
}
首页代码：其中获取servlet传过来的值是forEach
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>Title</title>
<link rel="stylesheet" href="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="http://cdn.static.runoob.com/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/js/bootstrap.min.js"></script>
</head>
<body>
<p>
<a href="addData.jsp" class="btn btn-primary btn-lg" role="button">添加数据</a>
</p>
<!--项目列表 主页-->
<table class="table table-striped" style="width: 100%">
<caption>信息全部详情</caption>
<thead>
<tr>
<th>ID</th>
<th>姓名</th>
<th>年龄</th>
<th>班级</th>
<th>QQ</th>
<th>手机</th>
<th>状态</th>
<th>操作</th>
</tr>
</thead>
<tbody>
<c:forEach items="${listAll}" var="listall">
<tr>
<td>${listall.id}</td>
<td>${listall.name}</td>
<td>${listall.age}</td>
<td>${listall.banji}</td>
<td>${listall.qq}</td>
<td>${listall.shouji}</td>
<td>${listall.zhuangtai}</td>
<td><a href="/bianji.do?id=${listall.id}" id="bianji" >编辑</a>/<a href="/delete.do?id=${listall.id}" >删除</a></td>
</tr>
</c:forEach>
</tbody>
</table>
</div>
</body>
</html>
效果：
5.2添加数据
添加中，主要是ajax回调，$('#addform').serialize()可以从上往下找到表格里的值并作为数据发送给servlet，回调成功后会弹出一个友好提示框再返回到servlet中，是layui.js,去官网上直接下载即可，不过要注意的是，在form表单中，提交按钮type不能是submit，只能是button，否则不能用（一闪而过）。
<script >
function tijiao() {
// alert("ssss");
var AjaxURL = "/adddata.do";
// alert($('#addform').serialize());
$.ajax({
type: "POST",
dataType: "html",
url: AjaxURL,
data: $('#addform').serialize(),
success: function (result) {
var strresult = result;
layer.msg('插入成功,2秒返回主页', {
time: 2000 //2秒关闭（如果不配置，默认是3秒）
}, function(){
location.href="/homepage.do";
});
},
error: function (data) {
layer.open({
title: '插入提示'
,content: '插入失败'
});
}
})
}
</script>
页面代码：<td><a href="/bianji.do?id=${listall.id}" id="bianji" >编辑</a>/<a href="/delete.do?id=${listall.id}" >删除</a></td>这里面可以直接对编辑，删除进行处理（在跳转到servlet中处理）。
<%--
Created by IntelliJ IDEA.
User: liuzhitong
Date: 17/12/2
Time: 下午8:45
To change this template use File | Settings | File Templates.
--%>
<%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>Title</title>
<script src="http://cdn.static.runoob.com/libs/jquery/2.1.1/jquery.min.js"></script>
<link rel="stylesheet" href="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<script src="layui/layui.all.js"></script>
</head>
<body>
<caption>增加信息,(*为必填)</caption>
<form class="form-horizontal" role="form" accept-charset="utf-8" id="addform" >
<div class="form-group">
<label for="id_id" class="col-sm-2 control-label">(数字)*ID:</label>
<div class="col-sm-10">
<input type="number" class="form-control" name="dataid" id="id_id" placeholder="请输入ID">
</div>
</div>
<div class="form-group">
<label for="id_name" class="col-sm-2 control-label">*姓名:</label>
<div class="col-sm-10">
<input type="text" name="dataname" class="form-control" id="id_name" placeholder="请输入名字">
</div>
</div>
<div class="form-group">
<label for="id_age" class="col-sm-2 control-label">(数字)年龄:</label>
<div class="col-sm-10">
<input type="number" name="dataage" class="form-control" id="id_age" placeholder="请输入年龄">
</div>
</div>
<div class="form-group">
<label for="id_banji" class="col-sm-2 control-label">班级:</label>
<div class="col-sm-10">
<input type="text" name="databanji" class="form-control" id="id_banji" placeholder="请输入班级">
</div>
</div>
<div class="form-group">
<label for="id_qq" class="col-sm-2 control-label">QQ:</label>
<div class="col-sm-10">
<input type="text" name="dataqq" class="form-control" id="id_qq" placeholder="请输入QQ">
</div>
</div>
<div class="form-group">
<label for="id_shouji" class="col-sm-2 control-label">手机:</label>
<div class="col-sm-10">
<input type="text" name="datashouji" class="form-control" id="id_shouji" placeholder="请输入手机">
</div>
</div>
<div class="form-group">
<label for="id_zhuangtai" class="col-sm-2 control-label">状态:</label>
<div class="col-sm-10">
<input type="text" name="datazhuangtai" class="form-control" id="id_zhuangtai" placeholder="请输入状态">
</div>
</div>
<div class="form-group">
<div class="col-sm-offset-2 col-sm-10">
<button type="button" class="btn btn-default" onclick="tijiao()" >保存</button>
<a href="homepage.jsp" class="btn btn-default" role="button">返回</a>
</div>
</div>
</form>
</body>
<script >
function tijiao() {
// alert("ssss");
var AjaxURL = "/adddata.do";
// alert($('#addform').serialize());
$.ajax({
type: "POST",
dataType: "html",
url: AjaxURL,
data: $('#addform').serialize(),
success: function (result) {
var strresult = result;
// alert("插入成功");
layer.msg('插入成功,2秒返回主页', {
time: 2000 //2秒关闭（如果不配置，默认是3秒）
}, function(){
location.href="/homepage.do";
});
},
error: function (data) {
// alert("error:" + data.responseText);
layer.open({
title: '插入提示'
,content: '插入失败'
});
}
})
}
</script>
</html>
MainServlet.java中对接收的数据进行处理，接收数据直接用String name = request.getParameter("dataname");
else if(str.equals("/adddata.do")){
addServletData(request, response);
}
private void addServletData(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String id=request.getParameter("dataid");
System.out.print("ceshi---"+id);
String name = request.getParameter("dataname");
String banji = request.getParameter("databanji");
String dataqq = request.getParameter("dataqq");
String datashouji = request.getParameter("datashouji");
String datazhuangtai = request.getParameter("datazhuangtai");
int age =Integer.parseInt(request.getParameter("dataage"));
if (name.equals("") || id.equals("") ) {
} else {
String sql = "INSERT INTO information VALUES('" + id + "','" + name + "'," + age + ",'" + banji + "','" + dataqq + "','" + datashouji + "','" + datazhuangtai + "')";
panduan = daoConnection.addData(sql);
}
response.getWriter().write("yue");
}
到这里就插入成功了。
5.3编辑数据
在编辑jsp中也有ajax回调，用法和插入是一样的。当用户点击编辑的时候，首先url会带着该条数据的ID进入MainServlet.java进行查找该id的数据并且再带着数据list返回到编辑页面，在编辑页面点击保存按钮的时候再次进入servlet处理，而不是点击就直接进入编辑页面。
<a href="/bianji.do?id=${listall.id}" id="bianji" >编辑</a>/<a href="/delete.do?id=${listall.id}" >删除</a></td>
处理代码：
else if(str.equals("/bianji.do")){
bianjiData(request,response);//仅仅是把之前的数据待到编辑.jsp页面。
}
private void bianjiData(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String id=request.getParameter("id");
System.out.print("------"+id);
String chaSql="SELECT * FROM information WHERE id = '"+id+"'";
List<Information> listDan=daoConnection.updataData1(chaSql);
request.getSession().setAttribute("listDan",listDan);
request.getRequestDispatcher("bianji.jsp").forward(request,response);
}
bianji.jsp点击保存按钮处理
else if(str.equals("/update.do")){
updateData(request,response);
}
private void updateData(HttpServletRequest request, HttpServletResponse response) {
String id=request.getParameter("dataid");
System.out.print("ceshi---"+id);
String name = request.getParameter("dataname");
String banji = request.getParameter("databanji");
String dataqq = request.getParameter("dataqq");
String datashouji = request.getParameter("datashouji");
String datazhuangtai = request.getParameter("datazhuangtai");
int age =Integer.parseInt(request.getParameter("dataage"));
if (name.equals("") || id.equals("") ) {
} else {
String sql = "UPDATE information set age="+age + ",banji='"+banji+"',qq='"+dataqq+"',shouji='"+datashouji+"',zhuangtai='"+datazhuangtai+"' where id='"+id+"'";
daoConnection.updataData2(sql);
flushpage(request,response);
}
}
private void flushpage(HttpServletRequest request, HttpServletResponse response) {
listAll = new ArrayList<>();
try {
listAll = daoConnection.queryAllData();
request.getSession().setAttribute("listAll", listAll);
request.getRequestDispatcher("homepage.jsp").forward(request, response);
} catch (SQLException e) {
e.printStackTrace();
} catch (ServletException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
编辑页面jsp全部代码：
<%--
Created by IntelliJ IDEA.
User: liuzhitong
Date: 17/12/2
Time: 下午8:45
To change this template use File | Settings | File Templates.
--%>
<%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>Title</title>
<%--<script src="http://cdn.static.runoob.com/libs/jquery/2.2.1/jquery.min.js"></script>--%>
<%--<script src="https://code.jquery.com/jquery-3.2.1.min.js"></script>--%>
<script src="js/jquery.min.js"></script>
<link rel="stylesheet" href="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<script src="layui/layui.all.js"></script>
</head>
<body>
<caption>编辑页面,(*为必填)</caption>
<form class="form-horizontal" role="form" accept-charset="utf-8" id="addform" >
<c:forEach items="${listDan}" var="listdan">
<div class="form-group">
<label for="id_id" class="col-sm-2 control-label">(数字)*ID:</label>
<div class="col-sm-10">
<input type="number" readonly="true" class="form-control" name="dataid" value="${listdan.id}" id="id_id" placeholder="请输入ID">
</div>
</div>
<div class="form-group">
<label for="id_name" class="col-sm-2 control-label">*姓名:</label>
<div class="col-sm-10">
<input type="text" readonly="true" name="dataname" class="form-control" value="${listdan.name}" id="id_name" placeholder="请输入名字">
</div>
</div>
<div class="form-group">
<label for="id_age" class="col-sm-2 control-label">(数字)年龄:</label>
<div class="col-sm-10">
<input type="number" name="dataage" class="form-control" value="${listdan.age}" id="id_age" placeholder="请输入年龄">
</div>
</div>
<div class="form-group">
<label for="id_banji" class="col-sm-2 control-label">班级:</label>
<div class="col-sm-10">
<input type="text" name="databanji" class="form-control" value="${listdan.banji}" id="id_banji" placeholder="请输入班级">
</div>
</div>
<div class="form-group">
<label for="id_qq" class="col-sm-2 control-label">QQ:</label>
<div class="col-sm-10">
<input type="text" name="dataqq" class="form-control" value="${listdan.qq}" id="id_qq" placeholder="请输入QQ">
</div>
</div>
<div class="form-group">
<label for="id_shouji" class="col-sm-2 control-label">手机:</label>
<div class="col-sm-10">
<input type="text" name="datashouji" class="form-control" value="${listdan.shouji}" id="id_shouji" placeholder="请输入手机">
</div>
</div>
<div class="form-group">
<label for="id_zhuangtai" class="col-sm-2 control-label">状态:</label>
<div class="col-sm-10">
<input type="text" name="datazhuangtai" class="form-control" value="${listdan.zhuangtai}" id="id_zhuangtai" placeholder="请输入状态">
</div>
</div>
<div class="form-group">
<div class="col-sm-offset-2 col-sm-10">
<button type="button" class="btn btn-default" onclick="tijiao()" >保存</button>
<a href="homepage.jsp" class="btn btn-default" role="button">返回</a>
</div>
</div>
</c:forEach>
</form>
</body>
<script >
function tijiao() {
var AjaxURL = "/update.do";
$.ajax({
type: "POST",
dataType: "html",
url: AjaxURL,
data: $('#addform').serialize(),
success: function (result) {
var strresult = result;
layer.alert('修改成功', function(index){
layer.close(index);
location.href="/homepage.do";
});
},
error: function (data) {
// alert("error:" + data.responseText);
layer.alert('修改失败', function(index){
layer.close(index);
});
}
})
}
</script>
</html>
5.4：删除一行数据，和编辑一样也是先带着id进入servlet处理，
else if(str.equals("/delete.do")){
deleteData(request,response, id);
}
private void deleteData(HttpServletRequest request, HttpServletResponse response, String ID) throws ServletException, IOException {
String deleteSql = "DELETE FROM information WHERE id = '" + ID + "'";
daoConnection.deleteData(deleteSql);
flushpage(request, response);
}
到此，增删查改就全部写完了，上面代码看似复杂，其实没一个功能都是独立的，也就是只写一个增加功能，也是可以运行的。哦对了，还有一个wendang.jsp，这个大家可以仿着来。
总效果图：
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